// Do this as the first thing so that any code reading it knows the right env.
process.env.BABEL_ENV = 'development'
process.env.NODE_ENV = 'development'

// Makes the script crash on unhandled rejections instead of silently
// ignoring them. In the future, promise rejections that are not handled will
// terminate the Node.js process with a non-zero exit code.
process.on('unhandledRejection', (err) => {
    throw err
})

// Ensure environment variables are read.
require('../config/env')

const fs = require('fs')
const chalk = require('react-dev-utils/chalk')
const webpack = require('webpack')
const WebpackDevServer = require('webpack-dev-server')
const clearConsole = require('react-dev-utils/clearConsole')
const checkRequiredFiles = require('react-dev-utils/checkRequiredFiles')
const {
    choosePort,
    createCompiler,
    prepareProxy,
    prepareUrls,
} = require('react-dev-utils/WebpackDevServerUtils')
const openBrowser = require('react-dev-utils/openBrowser')
const semver = require('semver')
const paths = require('../config/paths')
const configFactory = require('../config/webpack.config')
const createDevServerConfig = require('../config/webpackDevServer.config')
const getClientEnvironment = require('../config/env')
const react = require(require.resolve('react', { paths: [paths.appPath] }))

const env = getClientEnvironment(paths.publicUrlOrPath.slice(0, -1))
const useYarn = fs.existsSync(paths.yarnLockFile)
const isInteractive = process.stdout.isTTY

// Warn and crash if required files are missing
if (!checkRequiredFiles([paths.appHtml, paths.appIndexJs])) process.exit(1)

// Tools like Cloud9 rely on this.
const DEFAULT_PORT = parseInt(process.env.PORT, 10) || 9999
const HOST = process.env.HOST || '0.0.0.0'

if (process.env.HOST) {
    console.log(
        chalk.cyan(
            `Attempting to bind to HOST environment variable: ${chalk.yellow(
                chalk.bold(process.env.HOST)
            )}`
        )
    )
    console.log(
        `If this was unintentional, check that you haven't mistakenly set it in your shell.`
    )
    console.log(
        `Learn more here: ${chalk.yellow('https://cra.link/advanced-config')}`
    )
    console.log()
}

// We require that you explicitly set browsers and do not fall back to
// browserslist defaults.
const { checkBrowsers } = require('react-dev-utils/browsersHelper')
checkBrowsers(paths.appPath, isInteractive)
    .then(() => {
        // We attempt to use the default port but if it is busy, we offer the user to
        // run on a different port. `choosePort()` Promise resolves to the next free port.
        return choosePort(HOST, DEFAULT_PORT)
    })
    .then((port) => {
        if (port == null) {
            // We have not found a port.
            return
        }

        const config = configFactory('development')
        const protocol = process.env.HTTPS === 'true' ? 'https' : 'http'
        const appName = require(paths.appPackageJson).name

        const useTypeScript = fs.existsSync(paths.appTsConfig)
        const tscCompileOnError = process.env.TSC_COMPILE_ON_ERROR === 'true'
        const urls = prepareUrls(
            protocol,
            HOST,
            port,
            paths.publicUrlOrPath.slice(0, -1)
        )
        const devSocket = {
            warnings: (warnings) =>
                devServer.sockWrite(devServer.sockets, 'warnings', warnings),
            errors: (errors) =>
                devServer.sockWrite(devServer.sockets, 'errors', errors),
        }
        // Create a webpack compiler that is configured with custom messages.
        const compiler = createCompiler({
            appName,
            config,
            devSocket,
            urls,
            useYarn,
            useTypeScript,
            tscCompileOnError,
            webpack,
        })
        // Load proxy config
        const proxySetting = require(paths.appPackageJson).proxy
        const proxyConfig = prepareProxy(
            proxySetting,
            paths.appPublic,
            paths.publicUrlOrPath
        )
        // Serve webpack assets generated by the compiler over a web server.
        const serverConfig = createDevServerConfig(
            proxyConfig,
            urls.lanUrlForConfig
        )
        const devServer = new WebpackDevServer(compiler, serverConfig)
        // Launch WebpackDevServer.
        devServer.listen(port, HOST, (err) => {
            if (err) return console.log(err)

            if (isInteractive) clearConsole()

            if (env.raw.FAST_REFRESH && semver.lt(react.version, '16.10.0')) {
                console.log(
                    chalk.yellow(
                        `Fast Refresh requires React 16.10 or higher. You are using React ${react.version}.`
                    )
                )
            }

            console.log(chalk.cyan('Starting the development server...\n'))
            openBrowser(urls.localUrlForBrowser)
        })

        ;['SIGINT', 'SIGTERM'].forEach(function (sig) {
            process.on(sig, function () {
                devServer.close()
                process.exit()
            })
        })

        if (process.env.CI !== 'true') {
            // Gracefully exit when stdin ends
            process.stdin.on('end', function () {
                devServer.close()
                process.exit()
            })
        }
    })
    .catch((err) => {
        if (err && err.message) console.log(err.message)

        process.exit(1)
    })
